The present invention concerns a damping device for moveable furniture parts, comprising:                a damper housing,        a fluid chamber arranged in the damper housing and in which a piston is moveably supported, and        a ram connected to the piston. Arranged between the damper housing and the ram is at least one seal for sealing off the fluid chamber, and the ram passes through the seal.        In addition, a compensating chamber which is in fluid-conducting relationship with the fluid chamber extends laterally parallel to the fluid chamber and there there is arranged at least one deformable compensating body in the compensating chamber for compensation for a change in volume due to the ram immersing into the fluid chamber.        
The damping action of fluid dampers is substantially based on the flow resistance of a damping fluid present in a fluid chamber. When the piston is subjected to pressure, it is displaced relative to the fluid chamber, in which case the fluid flows from one cylinder chamber into another cylinder chamber by way of through-flow openings of the piston or between the piston and fluid chamber. In order to prevent the liquid damping medium from escaping from the damper, the ram or the piston rod is sealed relative to the fluid chamber by a seal, wherein the ram or the piston rod is slidingly displaceable against that seal. The compensating chamber is provided to compensate for the volume of the piston rod or ram as it moves into or out of the fluid chamber so that failure of the damping device due to the increased pressure loading of the inwardly moving piston rod is prevented.
WO 2010/108203 A1 to the present applicant discloses a furniture hinge having a damping device which has two fluid chambers connected by way of a passage. Arranged in one fluid chamber is a device having a displaceable piston or a displaceable material portion provided to compensate for the volume of the piston rod.
DE 199 01 517 A1 describes a door closer having a hydraulic piston-cylinder unit, wherein a compensating body forming the pressure compensating space is arranged in one of the hydraulic spaces. The compensating body is connected to a piston component and is of a bag-form configuration, wherein the inwardly moving volume of the piston rod can be compensated by the compensating body present in the hydraulic space.
EP 1 241 374 A1 and JP 60-018631 respectively describe damping devices having a piston guided in a fluid chamber and a compensating chamber extending parallel to the fluid chamber, wherein the seal arranged between the damper housing and the ram and the compressible material disposed in the compensating chamber are formed separately from each other.
In the state of the art, a relatively large number of individual parts are necessary for the damping device, and those parts, due to the desired compact structure of furniture dampers, are additionally very small and delicate, in which respect assembly of the damper is also relatively complicated and laborious.